Eelctrical Help - Off Color
Printed From: Unofficial Allis
Category: Allis Chalmers
Forum Name: Farm Equipment
Forum Description: everything about Allis-Chalmers farm equipment
URL: https://www.allischalmers.com/forum/forum_posts.asp?TID=201504
Printed Date: 27 Sep 2024 at 1:43pm
Software Version: Web Wiz Forums 11.10 - http://www.webwizforums.com
Topic: Eelctrical Help - Off Color
Posted By: calico190xt68
Subject: Eelctrical Help - Off Color
Date Posted: 26 May 2024 at 11:32am
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This isn't even a tractor but a semi but I think the electrical wizards on here can confirm my findings. I have 855 Big Cam 3 Cummins with PT Pump and it won't start without screwing in the solenoid bypass. My wiring is really bad under the dash so I decided to bypass and I used a 15 Amp fuse inline to do a direct test to the battery and it blew the fuse. Solenoid only has one post so I assume it gets it ground from the engine. I removed the Solenoid and attached wire direct from post to positive and negative to the solenoid frame and it did not move back and forth, but it sparks like crazy as if it is shorted out? Maybe that is what happens when they go bad? I thought it should just sit there and do nothing. I think it is a $50 part so not bad as far as farm equipment goes. ------------- 80 7010, 80 7020. 67 190XTD Series I w/500 Loader, AC 2000 Plow, AC 4 row Planter, AC 77G Rake, Member Indiana A-C Partners, Member TAC |
Replies:
Posted By: Les Kerf
Date Posted: 26 May 2024 at 12:27pm
Assuming a 24 volt system: 24Volts divided by 15 Amps = 1.6 Ohms. I suspect yours will measure somewhat less resistance than that. Even if the solenoid required 6 Amps to operate it should read 4 Ohms. Pretty sure you need a new solenoid. |
calico190xt68 wrote:Posted By: BobPaulusCentrOH
Date Posted: 26 May 2024 at 12:30pm
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Sounds like solenoid coil is shorted. If you have an ohmmeter, a good coil will have some resistance, but a shorted coil will have zero resistance. The direct connection to the battery blowing a 15 ampere fuse indicates that. Also check wiring to coil for shorts also. Good Luck! Bob
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Posted By: HudCo
Date Posted: 26 May 2024 at 12:57pm
| i dont think any thing that came with a big cam iii will be 24v but just see what voltage you have at the shutoff soliniod and replace the soliniod or just keep the srew turned in an d keep killing it with the clutch shut off soliniods are readly avaliable from cummins |
Posted By: Les Kerf
Date Posted: 26 May 2024 at 7:30pm
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I just measured a brand new 12 Volt Ford starter solenoid: 3 Ohms Tripping a 15 amp breaker would require less-than 1 Ohm on a 12 volt circuit.
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Posted By: calico190xt68
Date Posted: 27 May 2024 at 5:20pm
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Thanks for the help. I don't see how it could be anything other than a shorted solenoid. I ordered a new fuel cutoff solenoid. I will report back on what happens. I have a feeling that there may be a fuse that is blown for the original wire but I haven't found it yet. It is really hard to trace these wires in this old truck. I will probably run a new wire to the ignition switch, if I can't find it. ------------- 80 7010, 80 7020. 67 190XTD Series I w/500 Loader, AC 2000 Plow, AC 4 row Planter, AC 77G Rake, Member Indiana A-C Partners, Member TAC |
Posted By: calico190xt68
Date Posted: 01 Jun 2024 at 8:04pm
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So I bought a new fuel cutoff solenoid and the engine now starts so that was the issue. However, the original wire running to the solenoid does not have power now. I can't find the fuse so I am guessing the wire may have gone bad when it shorted out. I thought I would run a new wire with an inline fuse. I am not sure what size fuse it should be? How do you properly size the fuse for the solenoid of the cutoff fuel? I also found some serious wiring issues with the key switch wires. One was rubbed almost in half. Another was laying in a disconnected state. I also determined that the locking nut holding the key switch in place was stripped and letting the key rotate, causing wires to get twisted. So, I bought what I thought was a true replacement (LS411) ignition cylinder, removed the key cylinder with a paper clip, inserted into the new cylinder and fit perfectly. So, I thought I had it fixed but it is not. I hooked up the newly run solenoid wire to the solenoid terminal on the new key switch (like the old switch) and it starts but as soon as I let off of the key it dies. I thought the solenoid terminal supplied power after it was started but I must be wrong? Or the new ignition switch terminal is different than the old one. What do I need to do to continue to supply power to the solenoid wire after I start and let off of the key? As well, it has to stop supplying power when the key switch is turned off. I also know the old key ignition switch was not original to the truck so it was a rig job to begin with. It originally had a push button start like a tractor but that had been disabled. The ignition switch is from a 1981 chevy truck. So, it is a battle for me to figure out the wiring. Sorry it isn't directly related to AC but I do appreciate the help. ------------- 80 7010, 80 7020. 67 190XTD Series I w/500 Loader, AC 2000 Plow, AC 4 row Planter, AC 77G Rake, Member Indiana A-C Partners, Member TAC |
Posted By: 8070nc
Date Posted: 01 Jun 2024 at 8:45pm
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Theres a terminal on that switch thats hot in start and run. Id take a tester and find out which one it is. Thats were your solenoid wire should go. Hope that helps you ------------- 1984 80780 1957 D14 DES 300 with 25000 engine 616 tractor |